The present invention relates to low calorie dipeptide sweetener salts which can be used in heated or cooked foods and have no disagreeable aftertaste. More specifically, the invention relates to aspartyl dipeptide sweetener sulfate and organosulfonate salts which have a high thermal stability and dissolve rapidly in aqueous media.
Known dipeptide sweeteners are aspartyl-substituted alanine compounds having many times the sweetening power of sucrose. They were discovered in the 1960's and have been developed as low calorie substitutes for sugar. They do not have the bitter aftertaste of artificial sweeteners and since they are composed of natural amino acids, they are naturally assimilated.
Pharmacologically acceptable acid salts of the dipeptide sweeteners have been described as having about the same sweetening effect as the free base sweeteners. In addition, they dissolve quickly in aqueous media; see U.S. Pat. Nos. 4,029,701 and 3,714,139. Known dipeptide salts include the hydrohalide salts, the hydrogen sulfate salt, the dihydrogen phosphate salt, and similar salts as described in U.S. Pat. Nos. 4,031,258 and 4,029,701.
Despite the attractiveness of the use of the dipeptide sweeteners and their acid salts as sweeteners, difficulties remain. The free base and known salt forms of the sweetners, in general, exhibit little thermal stability. Consequently, when used in foodstuffs which require cooking or when mixed with food ingredients and put through a heating process such as pasteurization, they tend to be thermally degraded. Moreover, their low thermal stability adversely affects their shelf lives. As a result, the free base and known salt forms of sweeteners are not particularly useful for multipurpose foodstuff applications and cannot be universally substituted in place of sugar.